Aquaporin is present inside a biomembrane of a plant and is a protein which is responsible for the transport of water. It is categorized into four separate groups including plasma membrane intrinsic protein (PIP), tonoplast intrinsic protein (TIP), nodulin 26-like intrinsic protein (NIP), and small and basic intrinsic protein (SIP) (Luu and Maurel, 2005, Plant Cell environ. 28: 85-96). Among these, expressions of some genes of the NIP group of Arabidopsis thaliana have been reported to be root specific and promoters for such genes have a root specific activity (Masahiro M, et. al., 2006, 47: 1420-1426).
Aquaporin gene from Capsicum annuum (a species of a hot pepper) is one kind of tonoplast intrinsic protein and there has no report until now indicating that a promoter from tonoplast intrinsic Aquaporin gene has a root specific activity.
Recently, various studies have been made to produce commercially useful materials based on a genetic engineering technology, i.e., with introduction of a foreign gene in a plant. When a commercially useful foreign gene is desired to be expressed in a transformed plant, a promoter that is related to expression of the gene is also required. For this, a promoter from cauliflower mosaic virus (CaMV35S), which is expressed in any type of a tissue of a plant, has been widely used. However, when it is desired to produce a useful material only in a root or when expression of a foreign gene in tissues other than a root has a harmful effect on a plant, a promoter which can induce expression specifically in a root is required.
In Korean Patent Reg. No. 0604186, a nucleotide sequence of a promoter for root specific expression of a sweet potato (Ipomoea batatas L.) storage roots, a vector for transient and root specific plant expression comprising the promoter sequence, and a method for transient expression in storage roots of a plant by using the expression vector are disclosed. In Korean Patent Reg. No. 0574563, a root specific expression promote from Arabidopsis thaliana and a vector comprising the promoter for root specific expression in plant are disclosed. However, these promoters are different from the promoter of the present invention.